The embodiment relates to a light emitting device, a light emitting device package, a lighting system, and a manufacturing method of light emitting device.
A light emitting device (LED) includes a p-n junction diode having a characteristic of converting electric energy into light energy. The p-n junction diode can be formed by combining group III-V elements of the periodic table. The LED can represent various colors by adjusting the compositional ratio of compound semiconductors.
When forward voltage is applied to the LED, electrons of an n layer are bonded with holes of a p layer, so that energy corresponding to an energy gap between a conduction band and a valance band may be generated. This energy is mainly realized as heat or light, and the LED emits the energy as the light.
A nitride semiconductor represents superior thermal stability and wide band gap energy so that the nitride semiconductor has been spotlighted in the field of optical devices and high-power electronic devices. In particular, blue, green, and UV light emitting devices employing the nitride semiconductor have already been developed and extensively used.
Recently, the semiconductor growth structure or the epitaxial growth process has been improved to develop a light emitting device having superior light extraction efficiency.
In order to improve the light extraction efficiency, a technology for patterning a transparent electrode has been suggested. However, when the transparent electrode is patterned, a light emitting structure may be damaged due to plasma impact, crystalline fracture occurs during the etching process for the transparent electrode and photoresist scum remains due to the micro patterning.